My heater does not and there is no wet spot on the floor board. I just changed the thermastat. Do you have an idea if what it could be?

I'm guessing you have no heat! since you just replaced the t stat
first make sure there is no air lock in the cooling system
i don't know what engine you have but there are air bleed screws
if there is no air then grab the heater hoses make sure both are HOT
if not then you have a flow problem back flushing the heater core may work have you added any kind of STOP LEAK to the cooling system that will plug up a heater core
if both heater hoses are hot and you have good engine temperture
then check the temperture motor on the right side of the heater box
remove glove box and hush pannel
as you move the temp. from hot to cold watch and see if the temp. motor is moving
hope this helps let me know but next time more info would help

Sometimes these are a real pain to bleed. double check your cooling resevoir and top off as neccessary. once you have done that, rev the engine to about 2000rpm's while the heater is on. this will help bleed the system also and you should feel heat rather quickly. the running temp on these engines is around 220 degrees farenheit. happy holidays

If the blower is working then the valve which allows the hot water (coolant) into the heater coil is not working. Find the valve under the hood on or near the firewall. It will have 3/4 inch heater hoses connected to it. Manually open the valve and check to see if you have heat. If so your heater valve cable needs replacing. I goes from the temerature lever on the dash to the valve under the hood.